Method for combating weeds in crop cultures

ABSTRACT

WHEREIN Hal represents bromine or chlorine and R1 and R2 each represents a lower alkyl.   This invention relates to the use as herbicides of compounds having the formula

iinited States Patent Inventors Appl. No.

Filed Patented Assignee Priority METHOD FOR COMBATING WEEDS [N CROPCULTURES 23 Claims, No Drawings lint. Cl A0111 9/24 [50] FieldoISearch71/120 [56] References Cited UNITED STATES PATENTS 3,288,586 ll/l966Littler 7 [I120 FOREIGN PATENTS 1,062,059 7/1959 Germany 7 l/l20 PrimaryExaminerJames 0. Thomas, Jr. Anomeys- Harry Goldsmith, Joseph G. Kolodnyand Bryant W. Brennan ABSTRACT: This invention relates to the use asherbicides of compounds having the formula 0 R BrNHCN Hal 2% R,

fl X I wherein Hal represents bromine or chlorine and R and R, eachrepresents a lower alkyl.

METHOD FOR COMBATING WEEDS IN CROP I CULTURES This is a divisionalapplication of our application Ser. No. 543,541, filed Apr. 19, 1966,now US. Pat. No. 3,497,541, which, in turn, is a continuation-in-part ofour application, Ser. No. l9l,442, filed May 1, i962, now US. Pat. No.3,228,851.

The present invention relates to new compounds of the general formulawherein Hal represents a halogen atom, more particularly a bromine orchlorine atom and R, and R each represents a lower alkyl radical.

As a preferred embodiment the present invention relates to the compoundof the formula wherein Hal, R, and R have the meaning set forth above informula l), with a brominating agent. This process has the advantagethat it leads to the production of the valuable compounds of the generalformula (I) in an especially simple and economical manner. The smoothand unitary course of the reaction could not be foreseen, since thestarting materials to be brominated contain other reactive groups, forexample, the

group into which the brominemight be expected to enter.

As starting material to be brominated by this process there isespecially to be mentioned the compound of the formula The brominationof the starting compounds may be carried out in the presence or absenceof water.

The urea derivatives used as starting materials are advantageouslybrominated in the presence of a solvent or dispersing medium in whichthey are dissolved or suspended and, if desired, in the presence of anagent capable of binding acid, for example, sodium acetate.

As solvents or dispersing media for the starting materials to bebrominated there may be used, for example, glacial acetic acid,chloroform, carbon tetrachloride, nitrobenzene, sulfuric acid, water orpyridine.

The bromination may be carried out with bromine itself or with acompound yielding bromine. There may be used organic and inorganiccompounds containing bromine that are known to be suitable forbrominating organic substances and compounds which yield bromine oftheir own accord or liberate bromine during the reaction. Examples are:hypobromous acid or salts thereof, especially alkali metal salts oralkaline earth metal salts, such as sodium hypobromite or calciumhypobromite, organic compounds that yield bromine, such asN-bromo-carboxylic acid amides or imides, especiallyN-bromo-succinimide, addition compounds of bromine with organiccompounds, for example with pyridine, such as pyridine dibromide andsimilar brominating agents. The bromination is advantageously carriedout at temperatures between 60 C. and l00 C., preferably at temperaturesbetween 65 and C.

The invention also provides preparations for combating undesirable plantgrowth and pests, more particularly harmful nematodes, micro-organismssuch as fungi, which comprise as an active substance a compound of theabove general formula, and an inert carrier, a solvent, a diluent, anemulsifier, a dispersing agent, a wetting agent, an adhesive agent, afertilizer, or another fungicide, bactericide, a nematocide, or aninsecticide, or another herbicide or a molluscicide.

Among the aforesaid preparations those which are specially suitable aspesticides or herbicides are those which contain as active substance thecompound of the formula OCH; Br -NH-fi N\ The active substances may beused in an emulsified, dispersed or dissovled form or in a dustingpreparation.

For preparing solutions suitable for spraying as such there may be used,for example, organic solvents boiling above C. e.g. mineral oilfractions boiling above 100 C., such as diesel oil or kerosene, or coaltar oils or oils of vegetable or animal origin, or hydrocarbons, such asalkylated naphthalenes, tetra-hydronaphthalene, if desired, with the useof xylene mixtures, cyclohexanols, ketones, or chlorinated hydrocarbons,such as tetrachlorethane, trichlorethylene or triortetra-chlorobenzenes.

As preparations that can be diluted with water to yield aqueous liquorsfor application as such there may be mentioned emulsion concentrates,pastes or wettable powders. As emulsifying or dispersing agents thereare used nonionic products, such as condensation products of aliphaticalcohols, amines or carboxylic acids containing a hydrocarbon radicalhaving 10 to 30 carbon atoms with ethylene oxide, such as a condensationproduct of octadecyl alcohol with 25 to 30 mols of ethylene oxide or ofsoya bean oil fatty acid with 30 mols of ethylene oxide or of commercialoleylamine with 15 mols of ethylene oxide or of dodecyl mercaptan with12 mols of ethylene oxide. As anionic emulsifying agents there may bementioned the sodium salt of dodecyl alcohol sulfuric acid ester, thesodium salt of dodecyl-benzene sulfonic acid, the potassium ortriethanolamine salt of oleic acid or of abietic acid or of a mixture ofthese acids, or the sodium salt of a petroleum sulfonic acid. Ascationic dispersing agents there may be used quaternary ammoniumcompounds, such as cetyl-pyridinium bromide or dihydroxyethyl-benzyl-dodecylammonium chloride.

As solid carriers for making dusting or strewing powders there may beused talcum, kaolin, bentonite, calcium carbonate or calcium phosphate,or carbon cork meal or wood meal or other materials of vegetable origin.It is very advantageous to make up the preparations in a granulatedform. The preparations in their various forms may also have incorporatedtherewith in the usual manner substances that improve theirdispersibility, adhesion, resistance to rain or penetrating power, suchas fatty acids, resins, glue, casein or, for example, alginates Thepreparations that have a selective action may also be used inconjunction with, for example, in admixture with a fertilizer.

EXAMPLE 1 107 grams of N-(3-chloro-phenyl)-N'-methoxy-N-methylurea aredissolved in 500 cc. of glacial acetic acid, 41 grams of anhydroussodium acetate are added, and the bromination is carried out at 80 C.with 80 grams Br dissolved in glacial acetic acid. After 1 hour at 80the mixture is poured into ice.

The yield ofcrude N-(4-bromo-3-chlorophenyl)-N-methyl- N'-methoxy-ureais l2l grams. The product melts at 94-96 C. after recrystallization fromacetonitrile, melts at 945 to 955 C.

Analysis: C l-l N Br Cl.

Calculated: C 36.82 H 3.43

Found: C 36.9 H 3.3

EXAMPLE 2 a. To [0 parts of the compound of the above example 1 areadded 2 parts of sulfite cellulose waste liquor and 100 cc. of water,and the mixture is then subjected to intense grinding, to yield a stabledispersion of fine particle size which may be diluted as required withwater.

b. To 50 parts of the compound of example 1 are added 40 parts of kaolin(Bolus alba), 3.5 parts of a condensation product of l mol ofparatertiary octylphenol with 8 mols of ethylene oxide, 1.5 parts ofheptadecenylbenzimidazole sulfonate and parts of finely divided SiO themixture is then subjected to intense grinding, to yield a stabledispersion of fine particle size which may be diluted as required withwater.

EXAMPLE 3 a. An aqueous dilution of the dispersion according to example2 (b) was applied as a spray to a field planted with Irish potatoes(vaiety: Red Pontiac) at the rates of [.5 and 3 pounds of activesubstance per acre, 2 days after the planting of the potatoes. Thefollowing weeds were present in the test field:

Common Name Scientific Name Goosegrass Eleurine indica CrabgrassDigimria snnguinnlis Pangnlagrnss Digimrin derumbens BermudagrassCynodun durlylun Bahiagrass Paspalum noralum Pokcweed Phylularraamrrirnnu At the weed evaluation 2 months after the treatment, all theweeds present in the test field were completely or almost completelykilled. There was no phytotoxicity observed on the potatoes treated. Atthe yield evaluation 3 months after the planting date there was observedthat the test field treated according to the invention yielded at leastone-third more potatoes than an untreated control field. Good selectiveherbicidal effects were also obtained according to the method describedin this example with an application rate of 0.5 pound of activesubstance per acre.

EXAMPLE 4 Aqueous dilutions of the dispersion according to example 2 (b)were applied as sprays at rates decreasing from 8 to 0.25 pounds ofactive substance per acre to cultures of rice plants (paddy rice) in thefollowing manner:

1. soil incorporation. (Harrowed into the soil 2 days before the ricewas sown) rice) Evaluation 2. Preemergent application. (Spraying of thefield 1 day after the sowing of the rice) Evaluation in the case of l. 7weeks after the treatment In the case of 2. 7 weeks after the treatmentResults At the time of the evaluation an untreated control field washeavily infested with junglerice (Panicum) as the only weed present. Inthe case of the test fields treated according to the methods l. and 2.set forth above, it was observed that at the rate of 0.5 pound per acreof active substance the rice cultures were completely freed from thejunglerice.

EXAMPLE 5 An aqueous dilution of the dispersion according to example 2(b) was applied as a spray to a field sown with corn at a rate of 0.5pounds of active substance per acre, 2 days after the sowing of thecorn.

At the weed evaluation, 4 weeks after the treatment, it was observedthat the following weeds which had been predominant in the treatedfield, were completely killed: Lovegrass, Crabgrass and Pigweed. Therewas no phytotoxicity observed on the treated corn.

EXAMPLE 6 An aqueous dilution of the dispersion according to example 2(b) was applied as a spray to a field sown with cotton at a rate of 0.5pounds of active substance per acre, 2 days after the sowing of cottonplants.

At the weed evaluation, 4 weeks after the treatment, it was observedthat the following weeds which had been predominant in the treatedfield, were completely killed: Lovegrass, Crabgrass and Pigweed. Therewas no phytotoxicity observed on the treated cotton plants.

EXAMPLE 7 EXAMPLE 8 An aqueous dilution of the dispersion according toexample 2 (b) was applied as a spray to a field sown with peanuts at arate of 0.5 pounds of active substance per acre, 2 days after the sowingof peanuts.

At the weed evaluation, 4 weeks after the treatment, it was observedthat the following weeds which had been predominant in the treatedfield, were completely killed: Lovegrass, Crabgrass and Pigweed. Therewas no phytotoxicity observed in the treated peanut culture.

EXAMPLE 9 I a. Aq ueous dilutions of the dispersion according to example2 (b) were applied as sprays at rates of 0.75 and 1.5 pounds of activesubstance per acre to cultures of carrots, 2 weeks after the crops hadbeen sown. At the evaluation 4 weeks after the treatment, it wasobserved that the following weeds which had been predominant in thetreated test field, were practically completely killed: Lambsquarter,Ragweed and Smartweed. No phytotoxic effects on the treated carrots wereobserved.

b. An equally'good selective effect was observed by applying the activecompound under the conditions set forth above under (a) to a culture ofpeas.

EXAMPLE An aqueous dilution of the dispersion according to example 2 (b)was applied as a spray to 2 test fields sown with Lima beans andSoybeans, respectively at a rate of 0.5'pounds of active substance peracre, 2 daysafter the sowing of said plants.

At the weed evaluation, 4 weeks after the treatment. it was observedthat the following weeds which had been predominant in the treatedfields, were completely killed: Lovegrass, Crabgrass and Pigweed. Therewas no phytotoxicity observed in the treated crop plants.

EXAMPLE I l Microbicidal Effects a. From the compound described inexample I a solution of 1 percent by weight in propylene glycol wasprepared and tested against harmful fungi as described below: b. Thefollowing test organism .was used: Rhizopus nigricans. An aqueousbeerwort solution of 10 percent strength was used as nutrient medium ofwhich 9.5 ml. were put into a test tube. 0.5 ml. of the solution setforth above under (a) was added to the 9.5 ml. of nutrient medium. Inthis way a solution was obtained containing 500 pmp.m. of activesubstance. This was diluted with beerwort solution to a concentration ofactive substance of 60 p.p.m. The resulting solution was inoculated withI drop of a spore suspension of the above mentioned test organisms, andincubated for 8 days at 24 C. lt was then determined whether or not anygrowth of the test organism could be observed. The result is shown inthe following table:

Limit concentration at which inhibition Test organism of growth occursRhizopus nign'can s' 60 ppm 7 The effective amount of active compoundset forthabove did In the case of the this compound, however, nofungicidal effect could be observed, i.e.. the test solution wascompletely overgrown by the test organism.

EXAMPLE l2 Nematocidal Effect a. 10 g of the active substance describedin example I was dissolved in 100 g. of acetone, and 80 g. of anemulsifier, consisting of the condensation product from 1 mol ofpara-di-tertiary octylphenol with 8 mols of ethylene oxide, are added tothe solution. The resulting concentrate may be diluted with water adlibitum, for example to a concentration of 2.5 p.p.m. With increasingdilutions obtained in this manner the nematocidal effect againstPanegrellus redivivus was tested.

I The following table shows the result:

% mortality of panegrellus redivivus Active substance according toapplication (2.5 ppm) 93 b. As a comparative test the following compoundwas tested under exactly the same conditions as set forth aboveunder(a):

OCH;

t al compound-is the one OCH:

3. The method of claim 2 wherein weeds are selectively combated in acrop culture selected from the group consisting of potatoes, corn,tomatoes, peas, beans, soybeans, carrots, peanuts. rice and cotton.

4. The method of claim 1, wherein the crop culture is a potato culture.

5. The method of claim 1, wherein the crop culture is a corn culture.

6. The method of claim 1, wherein the crop culture is a tomato culture.

7. The method of claim 1, wherein culture.

8. The method of claim 1, wherein the crop culture is a bean culture.

9. The method of claim 1, wherein soybean culture.

10. The method of claim 1, wherein the crop culture is a carrot culture.

11. The method of claim 1, wherein the crop culture is a pcanut culture.

12. The method of claim I, wherein the crop culture is a rice culture.

13. The method of claim 1, wherein the crop culture is a cotton culture.

14. The method of claim 1, wherein the crop culture is a potato culture.

the crop culture is a pea the crop culture is a 20. The method of claimI, wherein the crop culture is a carrot culture.

21. The method of claim 1, wherein the crop culture is a peanut culture.

22. The method of claim 1, wherein the crop culture is a rice culture.

23. The method of claim I, wherein the crop culture is a cotton culture.

2. The method of claim 1 wherein the compound is the one of the formula3. The method of claim 2 wherein weeds are selectively combated in acrop culture selected from the group consisting of potatoes, corn,tomatoes, peas, beans, soybeans, carrots, peanuts, rice and cotton. 4.The method of claim 1, wherein the crop culture is a potato culture. 5.The method of claim 1, wherein the crop culture is a corn culture. 6.The method of claim 1, wherein the crop culture is a tomato culture. 7.The method of claim 1, wherein the crop culture is a pea culture.
 8. Themethod of claim 1, wherein the crop culture is a bean culture.
 9. Themethod of claim 1, wherein the crop culture is a soybean culture. 10.The method of claim 1, wherein the crop culture is a carrot culture. 11.The method of claim 1, wherein the crop culture is a peanut culture. 12.The method of claim 1, wherein the crop culture is a rice culture. 13.The method of claim 1, wherein the crop culture is a cotton culture. 14.The method of claim 1, wherein the crop culture is a potato culture. 15.The method of claim 1, wherein the crop culture is a corn culture. 16.The method of claim 1, wherein the crop culture is a tomato culture. 17.The method of claim 1, wherein the crop culture is a pea culture. 18.The method of claim 1, wherein the crop culture is a bean culture. 19.The method of claim 1, wherein the crop culture is a soybean culture.20. The method of claim 1, wherein the crop culture is a carrot culture.21. The method of claim 1, wherein the crop culture is a peanut culture.22. The method of claim 1, wherein the crop culture is a rice culture.23. The method of claim 1, wherein the crop culture is a cotton culture.